In the field of cell culture, cell culture containers are known which are usually made of transparent plastic, frequently as disposable or single-use containers, and which have one or more screw caps. The cell culture containers are used to propagate cells, i.e., to cultivate them, and to observe their growth. For this purpose, the cells to be cultivated are added together with a suitable nutrient medium to the container (often in the form of a bottle), where they can grow under appropriate environmental conditions. The interior of the cell culture container comprises a certain volume, which for this reason is called the culture volume. The environmental conditions usually consist of an ambient temperature of 37° C. with a CO2 content of 5% and a relative humidity (rH) of 95%. As soon as a certain percentage of the surface of the cell culture container is covered with the adherent cells (degree of confluence), the cells must either be harvested for further use or distributed over several new cell culture containers. In many cases, it is also necessary to renew the nutrient medium during cultivation (cell maintenance). For the replacement of the nutrient medium and/or the removal of adherent cells, possibly with or without nutrient medium, the term “fluid” is used here in a comprehensive sense.
For small quantities of cells to be cultivated, i.e., in the simplest case, the above-mentioned steps in the cell culture process are performed manually by appropriately trained technical assistants with the help of hand pipettes under a sterile laboratory hood. That is, the caps of the cell culture containers are unscrewed by hand, and, after the fluid has been added or removed, they are screwed back on by hand. Specially made, dedicated shaking machines and other laboratory equipment are already replacing substeps of the overall process, so that not all of the activities in question have to be carried out manually.
For larger quantities of cell cultures, fully automated solutions are available on the market, which perform all of the necessary steps by means of mechanical robots such as, for example, the 6-axis robots made by TAP and Kawasaki. With these robot solutions, the same cell culture containers as those used for manual processing can be used, which eliminates the cost of buying new cell culture containers. The disadvantage of the automated robot solutions, however, is that the throughput and the speed of processing is very limited, and it is very difficult if not impossible to carry out the steps of the process in parallel or in an interleaved manner.
The cell culture containers currently in use have screw-on caps or covers, which can be configured as desired with or without a vent membrane to ensure efficient CO2 exchange with the cells inside the bottle. An important aspect of these aerating or filter membranes is that the pore size of the membrane may not exceed 0.22 μm, because otherwise the membrane could not still be considered a sterile membrane.
There are also various special forms of cell culture containers with pierceable membranes configured to serve as, for example, hydrophobic filter membranes; an example of such a special container is the cell culture bottle “AutoFlask” sold by the company Greiner Bio-One. These types of cell culture containers are optimized for automated processes, are compatible with a large number of different cell culture systems and liquid handling systems, and comprise, for example, a physical surface treatment for adherent cells. The disadvantage of these products, however, is that the user is limited to containers of precisely the right shape, size, and surface properties. For this reason, systems of this type are so far not in widespread use.
German patent application DE 10 2013 201 069 of the applicant is directed toward a cell culture system with a fluid supply interface and a cell culture container specially conceived for it, wherein the cell culture container comprises a filling and/or vent opening and at least one coupling formation configured separately from the filling and/or vent opening, this coupling formation being configured in such a way that the container can be attached to and detached from a corresponding coupling formation of the fluid supply interface. This cell culture system, i.e., this cell culture container, is therefore also adapted specifically to the corresponding system or interface, for which reason only some or only very few of the standard cell culture containers used in the past are still usable. To equip an entire laboratory or production facility with these new cell culture containers therefore requires a very large investment.
It is therefore the object of the present invention to provide a technical teaching for a cap of a cell culture container, wherein the cap not only overcomes the disadvantages described above but is also usable with the standard cell culture containers used in the past, is producible at low cost, and comprises a simple structure.